I'm trying to get a system of referencing started on my site to help people with their trades etc..I was wondering if anyone had any clue on how to do something like this. the site Bartertown has a great system and is what I want but the admins don't give out the code so for those who don't know about it here is the process:

There are two tabs one to check a reference and another to post one. If you click post a reference you get a screen like this: <-Click to enlarge

there are 3 options 'good, neutral, and bad' if good is clicked +1 is added to your reputation, neutral none, and bad -1.

If you decided to click on check a reference, it's a search bar for a username, after putting one in you get a screen like this which shows all the references that were posted on the guy. <-Click to enlarge

I think this might be simpler than I think, but can I even do something like this in phbb3?Thats it!